Compact multi-filament textile tow and method of making the same

ABSTRACT

Multi-filament textile tow is rendered compact by continuously disposing wrapper yarns in generally helical paths around the tow, one such yarn being disposed in a clockwise manner and the other counter-clockwise.

United States Patent Rosenstein 1451 July 11, 1972 1541 COMPACTMUL'I'l-FILAMENT 2,449,595 9/1948 E1114 ..51/144 )1 Exm ow AND MEmon 1?3,565,127 2/1911 Nicely =1 61. ..51/140 x MQKIN THE ME l,563,307 11/1925Fm .51/144 G S 2,014,941 9/1935 Mcclllloch G! a] ..19/.46 (12] Inven or:N than Rmn. W t H rtford. Conn- 2,217,826 10/1940 Von bear ..51/144 x3.086.252 4/1963 Marley ..l9/.46 m] Wmwm) 3,166,885 1/1965 Bridgeman 61a! ....51/11 x 22 Filed: Jan. 21, 1910 3,365,872 [/1968 Field ..51/160 x3.438.195 4/1969 Km 61111.. .........51/144 [21] 3,478,506 11/1969Kawashima ..51/160 3.490.219 1/1910 Omwa 61 al. .51/34 1521 l9/.46,$7/2,

51/6. 51/ 1 3. 51/160 Primary Emminer-Donald E. Watkins 51 1 1111. c1.1101; 1/00 wor -P6111 & P601 [58] Flddolseuch ..51/3, 6, 2, 1a. 14, 15,16,

51/11. 18, 34, 144, 152, 160,163, [46; 19/.46 51 ABSTRACT Multi-filamenttextile tow is rendered compact by continu- [56] Rdennouflted ously H: rinsemmuy helical Paths UNITED STATES p -m around the tow, one web yarnbeing (Imposed 1n 9 clockmse manner and the other counter-clockwise.1,132,593 10/1929 Cannon ..51/144 2,087,303 1/1951 1264611 ct a]...51/144 x 12 can, Jr-win n nm INVENTOR. Norhon Rosenstein ATTORNEYS.

PATENTEDJULI I 1972 COMPACT MULTI-FILAMENT TEXTILE TOW AND METHOD OFMAKING THE SAME BACKGROUND OF THE INVENTION 1. Field of the InventionThis invention relates to a tow which is maintained in cohesive formwithout depending upon crimping, and which has the advantage that it canbe subjected to various handling and storage operations that are notnormal for tow, and in which individual filaments of the tow tend totangle, snag and break, and, panicularly by the activity of staticelectricity, to balloon, tangle, snag and break.

For example, according to this invention tow can be folded down into abox in a generally serpentine form, so that it has many successivelengths that are laid across and against each other, and transportedfrom place to place and stored indefinitely. Notwithstanding storage fera considerable period of time in this condition, the tow can bewithdrawn in untangled and substantially parallel form easily andsubjected to further processing, without ballooning, snagging ortangling of filaments from adjacent lengths of tow. ln dyeing orapplication of wetting-out agents, the ability to unwind or withdraw thetow is considerably facilitated.

The invention also relates to a method of making a compact towcontinuously and economically with high production rate.

2. Description of the Prior Art It is known to wrap a yarn helicallyaround a tow or other bundle of filaments, such as cotton yarn, forexample. Cotton yarn which has been used for manufacture of dungarees,for example, has been subjected to a helical wrap of binder yarn in onedirection only and then passed through a dye bath, following which thecotton yarns have been fed to a warp winder known in the trade as a longchain quiller for further processing of the cotton yarn. However, insuch a process it was found necessary to develop a special machine tounwind the helically wound binder yarn, in order to free cotton yarnsfor the quiller operation.

With respect to metallic monofilaments, it has also been known to formhelical wraps around copper wire, for example, to provide an interveninglayer between the copper wire and its insulation. In such cases,however, the copper wire has been a thick, heavy monofilament and therehas been no problem with respect to any compactness of multiplefilaments.

It has already been proposed to make novelty yarns by interlacing orplying yarns together. The U. S. Pat. to Berry No. 2,82 l ,835, forexample, discloses a cabled yarn composed of a plurality of multi-plyyarns, all of about the same denier, twisted together in a manner toproduce a braided appearance. It has also been proposed to twist morethan two yarns around each other, some clockwise and somecounterclockwise to produce a composite yarn having a braided appearance. Again, all of the yarns are of the same denier and the purposeof such twisting is not to provide coherence in a core yarn or tow butto produce from a plurality of yarns, all of which are twisted abouteach other, a novelty yarn having substantially zero twist. Such yarnsare, of course, to be distinguished sharply from tow.

Present uncrimped filament tows are known to use sizing agents formaintaining compactness and a certain amount of cohesion. Subsequently,such sizing agents must, at considerable effort and cost, be washed outto enable application of electrostatic agents required in the flockingindustry. In this case, since the tow holds together without sizingagents, the electrostatic agents needed in flocking can be appliedwithout prior washing out.

OBJECTS OF THE INVENTION Accordingly, it is an object of this inventionto provide a multi-filament tow product and a method of making the same,having particular advantage in the textile industry.

As another example, problems have existed in the precision cutting a towrepeatedly to furnish short lengths such as 0.03 of an inch, forexample, precision is required in producing a substantially uniformflock length, i.e., each individual fiber has essentially the samelength as all of the other individual fibers.

It has been found that, when tow is chopped by means of a knife in aflocking machine, substantially all of the filaments of the tow must becompactly presented with substantially parallel fibers. Otherwise, whenthe filaments are presented at random angles, because of ballooning theknife tends to chop individual flock filaments non-uniformly withrespect to filament lengths. It is a particular object of this inventionto provide a novel, compact tow which is ideally suited for cutting intoflock.

It has been found that, when a tow is snaked down into a box and thenwithdrawn, static electricity is developed which tends to causeballooning, and which in turn tends to cause in terrningling andsnagging of filaments from different lengths of the tow. An object ofthis invention is to overcome that difficulty.

It is also desired to process tow by snaking it down into a box, storingit and later withdrawing it in untangled parallel form and thensubjecting it to treatment in aqueous bath, such as a dye bath forexample. In such a circumstance, it is important and advantageous toprovide a means for maintaining the tow in a compact form, such thattangling does not occur upon storage or upon retrieval afier storage,but nevertheless maintaining tow in such a condition that it issufficiently open that it can be dried with relative ease afier it hasbeen processed in an aqueous bath. Ballooning is a particularlytroublesome problem after or during the drying operation. It isaccordingly another object of this invention to provide a compact towwhich has a substantial degree of openness for the purpose justdiscussed.

SUMMARY OF THE INVENTION It has been discovered that, when amuIti-filament tow, even when free of crimp, is subjected to wrapping ina generally helical manner with at least a pair of individual yarns orfilaments, one arranged helically in a clockwise manner and the otherarranged helically in a counter-clockwise manner, such yarns orfilaments being applied to the tow under substantially zero tension, atow is created which is sufiiciently compact that it can readily besnaked into a container, stored and later withdrawn without causingtangling or intenningling of individual filaments, which tow issufficiently open that it can be subjected to an aqueous bath andadvantageously and economically dried thereafter.

DESCRIPTION OF THE PREFERRED EMBODIMENTS This invention is directed to atow which consists of multiple filaments, indeed to tows which maycontain thousands of filaments or more. One typical tow to which thisinvention has been very advantageously applied has been a polyester towof about 500,000 denier, 6 denier per filament. Other tows for which theinvention is ideally suited include nylon tows, of only 3,000 denier, l5denier per filament, nylon tows of more than 1,000,000 denier, 3 denierper filament, and various tows of all known synthetic and cellulosicmaterials including nylon, polyester, polyethylene, polypropylene,cuprammonium fibers, rayon, acetate and various other syntheticcontinuous filamentary materials, regardless of denier per filament andregardless of total denier of the tow. The invention can also be appliedto tows composed of discontinuous fibers and of natural fibers includingcotton, wool and the like.

Indeed, this invention is applicable to tows that have been made up fromwaste fibers, after subjecting the waste fibers to (a) chopping orcutting, (b) carding or garnetting and (c) pindrafling to make thecomponent discontinuous filaments parallel. For many uses it isimportant to create such a tow and process it without crimping thediscontinuous filaments. If the flocking industry, wherein a cutterknife is provided for component filaments were crimped there might beadequate II'IIMA (HA1 cohesion for such a tow to hold together inprocessing, but the crimped filaments would not be of a suitable linearconfiguration for subsequent conversion into flock, for example.However, without any crimp and in the absence of some sort of adhesivesizing, the tow would completely fall apart in processing. Thus, it isimportant to provide a tow composed of discontinuous filaments in linearor non-crimped form, which nevertheless holds together in processing.

It is important in accordance with this invention that multi ple ends ofyarn are arranged in a generally helical manner and of opposite handabout the tow.

In applying the yarns to the tow, a controlled amount of tension may beapplied, but it has been discovered that a tight wrap for certain usesis usually unsatisfactory because of difficulty in drying the tow afterit has been immersed in an aqueous solution. For that reason, especiallywhen aqueous solutions are used, substantially zero tension ispreferably applied to both ends of yarn, or to all of them if more thantwo ends are used, when the ends of yarn are being helically wrappedaround the tow.

DRAWINGS FIG. l of the drawings shows an apparatus and method whichadvantageously causes the formation of a continuous, compact towembodying features of this invention.

FIG. 2 shows a length of continuous filament tow, shown broken off atthe ends, constructed and arranged in accordance with features of thisinvention, with the ends of some of the wrapping yarns shown broken offat random in order to illustrate the nature of the wrap more clearly.

FIG. 2a shows a length of tow similar to FIG. 2 but composed ofdiscontinuous filaments.

F IG. 3 shows tow, removed from storage in a box, being fed to aflocking machine to produce precision length fiock.

Referring to FIG. I, it will be seen that a machine frame supports aplurality of standards 11 on which are mounted a plurality ofcylindrical yarn packages collectively designated by the number 12, eachhaving a central, open core 13. The tow T which may be multi-filamenttow of any type or denier as already referred to herein, continuous ordiscontinuous, is continuously passed through the cores 13 of the yarnpackages 12. The tow T is continuously moved, preferably but notnecessarily at a constant speed, by means ofa pair of drive rollers l5,l5 and is delivered into a box 16. The tow is snaked into the bottom ofthe box by a distributing arm 17 which moves according to apredetermined path in order to distribute the tow substantially evenlyalong the bottom of the box, or upon the surface presented by tow thathas already been snaked into the box. The distributing arm 17 is movedback and forth, and from side to side (to allow for overalldistribution) by conventional mechanical means, not shown,

It will be observed that the yarn package 12a is mounted in such adirection that, when yarn is taken off over the end of the package, itis wrapped in a clockwise direction around the tow. it will be notedthat the second yarn package 12b is arranged with the yarn wound on thepackage on the opposite hand with respect to the yarn on the package126', subsequently, when the yarn is drawn over the end of the package,it is wrapped around the tow in a counter-clockwise manner, as shown.Similarly, the yarn is arranged to wrap in a clockwise manner from yarnpackage 12c, and in a counterclockwise manner from yarn package 12d,There is no practical limit to the number of yarn packages that may beutilized, but it is preferred to space the yarn packages longitudinallyalong the length of the tow, so that spaces exist between the variousyarns in the positions they occupy after they are applied to the tow.

A preferred manner of starting up is to provide substantially equallengths of yarn on each yarn package 12, and to handwrap the yarnsaround the tow until sufficient length of wrapped, compact tow isprovided so that the takeup device l5, takes up not only the tow but thespirally wrapped yarns as well. Then, by simply operating the drive ofthe take-up device, both the tow and all of the wrapper yarns areautomatically moved as a unit in a longitudinal direction.

It is important in accordance with this invention to apply the yarns tothe tow at substantially zero tension. The operation of the take-updevice l5, l5 gently unwinds the wrapper yarns from their packages atsubstantially zero tension.

For special purposes, requiring extreme degrees of com pactness, andparticularly where it is not intended to subject the wrapped tow to anaqueous bath, it is, of course, possible to apply conventional tensiondevices to the yarns as they pass from the packages to the tow, as iswell known in the textile industry, to provide a controlled tension foreach wrapper yarn. Also, for any specific purpose, it may be possible toapply more tension to one yarn than to the other yarn, and that each maybe applied at an individual controlled tension.

In those instances where zero tension is highly preferred, it has beennoted that when the diameter of the yarn on the package becomes toosmall, the yarn tension tends to increase because of friction betweenthe yarn and the end of the package core [3. Accordingly, it is highlydesired to control the diameter of the yarn package, so that the yarndoes not come off the end of the package at such an angle that it woulddrag against the package core 13, by replacing yarn packages andrewinding them, so that the packages always contain enough yarn to avoidfriction of the type referred to.

It will be appreciated that the compact tow manufactured in accordancewith this invention can be fed into a flock cutter of the type shown inFIG 3, and that the wrapper yarns maintain the filaments of the tow insubstantial parallelism, thus providing for a uniform presentation tothe cutter 20, resulting in the production of uniform flock lengths,Only the wrapper yarns themselves are presented at an angle to thelongitudinal axis of the tow, and they are cut into lengths that areonly infinitesmally longer than the filaments of the tow.

While flock cutting machines of various types are in existence, oneparticularly useful form of flock cutter, as shown in FIG. 3, consistsof a base block 21 which may be made of metal, for example, on which thecompact tow is continuously fed in a step-wise manner. In timed sequencewith the stepwire advancement of the tow, the guillotine-type knife 20reciprocates vertically up and down toward and away from the supportingblock 21. in this manner, the knife 20 operates in a manner similar to aguillotine and chops off short lengths of filaments F each time itdescends toward the block, Other types of flock cutters are also knownin the art.

In flock cutting, since each wrapper yarn will also become cut and willbecome flock, it is preferable to provide a wrapper yarn of the samefilament type and denier per filament as the tow. However, for otheruses, it is not essential to meet this requirement, and the wrapperyarns may indeed be composed of other types of filament, and of denierswhich differ from the deniers of the flock filament. For example, it ispossible to use wrapper yams which may later be dissolved for thepurpose of separating them from the flock filaments. Also, while it ispreferable to have both wrapper yarns applied clockwise andcounter-clockwise as heretofore discussed herein, it is also possible touse a single yarn for this purpose, and to cut the composite tow andwrapper yarn into flock.

Various other modifications may be resorted to without departing fromthe spirit and scope of this invention. For example, equivalent elementsmay be substituted for those specifically disclosed herein, certainfeatures of the invention may be used independently of other features,and various modifications may be made in the form of the method by whichthe wrapper yarns are applied to the tow, all within the spirit andscope of this invention as defined in the appended claims.

lclaimi l. A compact tow which may be stored with portions laid acrossor against each other and nevertheless withdrawn in essentiallyuntangled form without significant snagging or breakage of filaments,said tow comprising a multiplicity of substantially parallel textilefilaments packed into a container H MA nus! in the form of a pluralityof lengths laid closely adjacent to each other, said filaments of saidlengths being encased in a plurality of generally spirally arrangedcontinuous wrapper yarns, one wrapper yarn being spiraled under lowtension in contact with said textile filaments and another wrapper yarnbeing spiraled under low tension in a direction of opposite hand andbeing wrapped around said filaments and repeatedly and successively oversaid one wrapper yarn.

2. The tow defined in claim 1, wherein the wrapper yarn has essentiallythe same composition as the filaments of the tow, and wherein thefilaments of the yarn and the filaments of the tow have essentially thesame denier per filament.

3. The tow defined in claim I, wherein the filaments of the tow arecontinuous.

4. The tow defined in claim 1, wherein the filaments of the tow arediscontinuous.

5. The tow defined in claim 1, wherein the wrapper yarns are undersubstantially zero tension.

6. The tow defined in claim 1, wherein more than two wrapper yarns areapplied to the tow.

7. In a method of packaging a compact tow for transportation from oneplace to another, the steps which comprise continuously feeding a corecomprising a multiplicity of substantially parallel filaments along apredetermined path, continuously applying a continuous wrapper yarn in agenerally helical manner around the core and continuously applyinganother continuous wrapper yarn in a counter-directional generallyhelical manner around the core and repeatedly over the wrapper yarnfirst mentioned while maintaining said multiplicity of filaments in saidcore substantially parallel to each other, and packing the resulting towinto a package with a plurality of lengths of said tow laid alongsideand in contact with each other.

8. The method defined in claim 7, wherein the wrapper yarns aresubstantially inelastic and are disposed as a package having a coreopening, and wherein the core is substantially inelastic and isconducted through the core opening.

9. The method defined in claim 7, further characterized by continuouslychopping the filaments of the tow into flock filaments of substantiallyequal length while continuously concurrently chopping the wrapper yarns.

10. In a method of producing short cut filaments of substantially equallength, the steps which comprise:

continuously feeding a tow having a multiplicity of filaments along apredetermined path, continuously applying a plurality of continuouswrapper yarns having substantially the same composition as the towfilaments around said tow and substantially spirally with respect tosaid tow filaments while maintaining said tow filaments substantiallyparallel to one another, applying one such wrapper yarn in a clockwisemanner around said tow and applying another such wrapper yarn in acounterclockwise manner around said tow, continuously cutting thesubstantially parallel filaments of said tow into short cut filaments ofsubstantially equal length while concurrently cutting the wrapper yarns,the angle of the spiral being limited so that the wrapper yarns are cutinto lengths that are substantially similar to the lengths of the cutfibers produced from the tow filaments. 11. In a method of makinguniform, short, cut filaments which are suitable for formation of flockor the like, the steps which comprise continuously feeding a towcomprising a mul tiplicity of substantially parallel filaments along apredetermined path, continuously applying a first continuous wrapperyarn in a spiral manner around the tow, and continuously applyinganother wrapper yarn spirally in a counter-directional manner around thetow while maintaining said filaments substantially parallel to eachother, and continuously cutting the filaments of the tow into shortfilaments of substantially equal length while continuously concurrentlycutting the wrapper yarns to form additional short filaments ofsubstantially the samelength,

12. In a method of making a package containing a tow which is readilyremovable in an essentially untangled form from the package, withoutsignificant snagging or breakage of filaments, the steps which comprisecontinuously feeding a core comprising a multiplicity of substantiallyparallel filaments along a predetermined path, continuously applying acontinuous wrapper yarn spirally around the core, continuously applyinganother continuous wrapper yarn spirally in a counter-directional manneraround the core and repeatedly over the wrapper yarn first mentioned,while maintaining said multiplicity of filaments in said coresubstantially parallel to each other, and snaking the resulting wrappedtow into a container such that repeated lengths of said tow lie next toand touching each other, said wrapper yarns being arranged at suchangles with respect to the tow axis that they maintain the coherence ofthe fibers of the core such that there is substantially no significantamount of snagging between the filaments of adjacent lengths, when thetow is withdrawn from the package.

n i i 1 nun.

1. A compact tow which may be stored with portions laid across oragainst each other and nevertheless withdrawn in essentially untangledform without significant snagging or breakage of filaments, said towcomprising a multiplicity of substantially parallel textile filamentspacked into a container in the form of a plurality of lengths laidclosely adjacent to each other, said filaments of said lengths beingencased in a plurality of generally spirally arranged continuous wrapperyarns, one wrapper yarn being spiraled under low tension in contact withsaid textile filaments and another wrapper yarn being spiraled under lowtension in a direction of opposite hand and being wrapped around saidfilaments and repeatedly and successively over said one wrapper yarn. 2.The tow defined in claim 1, wherein the wrapper yarn has essentially thesame composition as the filaments of the tow, and wherein the filamentsof the yarn and the filaments of the tow have essentially the samedenier per filament.
 3. The tow defined in claim 1, wherein thefilaments of the tow are continuous.
 4. The tow defined in claim 1,wherein the filaments of the tow are discontinuous.
 5. The tow definedin claim 1, wherein the wrapper yarns are under substantially zerotension.
 6. The tow defined in claim 1, wherein more than two wrapperyarns are applied to the tow.
 7. In a method of packaging a compact towfor transportation from one place to another, the steps which comprisecontinuously feeding a core comprising a multiplicity of substantiallyparallel filaments along a predetermined path, continuously applying acontinuous wrapper yarn in a generally helical manner around the coreand continuously applying another continuous wrapper yarn in acounter-directional generally helical manner around the core andrepeatedly over the wrapper yarn first mentioned while maintaining saidmultiplicity of filaments in said core substantially parallel to eachother, and packing the resulting tow into a package with a plurality oflengths of said tow laid alongside and in contact with each other. 8.The method defined in claim 7, wherein the wrapper yarns aresubstantially inelastic and are disposed as a package having a coreopening, and wherein the core is substantially inelastic and isconducted through the core opening.
 9. The method defined in claim 7,further characterized by continuously chopping the filaments of the towinto flock filaments of substantially equal length while continuouslyconcurrently chopping the wrapper yarns.
 10. In a method of producingshort cut filaments of substantially equal length, the steps whichcomprise: continuously feeding a tow having a multiplicity of filamentsalong a predEtermined path, continuously applying a plurality ofcontinuous wrapper yarns having substantially the same composition asthe tow filaments around said tow and substantially spirally withrespect to said tow filaments while maintaining said tow filamentssubstantially parallel to one another, applying one such wrapper yarn ina clockwise manner around said tow and applying another such wrapperyarn in a counterclockwise manner around said tow, continuously cuttingthe substantially parallel filaments of said tow into short cutfilaments of substantially equal length while concurrently cutting thewrapper yarns, the angle of the spiral being limited so that the wrapperyarns are cut into lengths that are substantially similar to the lengthsof the cut fibers produced from the tow filaments.
 11. In a method ofmaking uniform, short, cut filaments which are suitable for formation offlock or the like, the steps which comprise continuously feeding a towcomprising a multiplicity of substantially parallel filaments along apredetermined path, continuously applying a first continuous wrapperyarn in a spiral manner around the tow, and continuously applyinganother wrapper yarn spirally in a counter-directional manner around thetow while maintaining said filaments substantially parallel to eachother, and continuously cutting the filaments of the tow into shortfilaments of substantially equal length while continuously concurrentlycutting the wrapper yarns to form additional short filaments ofsubstantially the same length.
 12. In a method of making a packagecontaining a tow which is readily removable in an essentially untangledform from the package, without significant snagging or breakage offilaments, the steps which comprise continuously feeding a corecomprising a multiplicity of substantially parallel filaments along apredetermined path, continuously applying a continuous wrapper yarnspirally around the core, continuously applying another continuouswrapper yarn spirally in a counter-directional manner around the coreand repeatedly over the wrapper yarn first mentioned, while maintainingsaid multiplicity of filaments in said core substantially parallel toeach other, and snaking the resulting wrapped tow into a container suchthat repeated lengths of said tow lie next to and touching each other,said wrapper yarns being arranged at such angles with respect to the towaxis that they maintain the coherence of the fibers of the core suchthat there is substantially no significant amount of snagging betweenthe filaments of adjacent lengths, when the tow is withdrawn from thepackage.